[PATCH v2 12/17] KVM: arm64: Support async PF ioctl commands

[Gavin Shan]

This supports ioctl commands for configuration and migration:

   KVM_ARM_ASYNC_PF_CMD_GET_VERSION
      Return implementation version
   KVM_ARM_ASYNC_PF_CMD_GET_SDEI
      Return SDEI event number used for page-not-present notification
   KVM_ARM_ASYNC_PF_CMD_GET_IRQ
      Return IRQ number used for page-ready notification
   KVM_ARM_ASYNC_PF_CMD_GET_CONTROL
      Get control block when VM is migrated
   KVM_ARM_ASYNC_PF_CMD_SET_SDEI
      Set SDEI event number when VM is started or migrated
   KVM_ARM_ASYNC_PF_CMD_SET_IRQ
      Set IRQ number during when VM is started or migrated
   KVM_ARM_ASYNC_PF_CMD_SET_CONTROL
      Set control block when VM is migrated

Signed-off-by: Gavin Shan <gshan@xxxxxxxxxx>
---
 arch/arm64/include/asm/kvm_host.h | 14 +++++++
 arch/arm64/include/uapi/asm/kvm.h | 19 +++++++++
 arch/arm64/kvm/arm.c              |  6 +++
 arch/arm64/kvm/async_pf.c         | 64 +++++++++++++++++++++++++++++++
 include/uapi/linux/kvm.h          |  3 ++
 5 files changed, 106 insertions(+)

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 6349920fd9ce..14b3d1505b15 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -778,6 +778,8 @@ void kvm_arch_async_page_present(struct kvm_vcpu *vcpu,
 				 struct kvm_async_pf *work);
 long kvm_arch_async_pf_hypercall(struct kvm_vcpu *vcpu,
 				 long *r1, long *r2, long *r3);
+long kvm_arch_async_pf_vm_ioctl(struct kvm *kvm, unsigned long arg);
+long kvm_arch_async_pf_vcpu_ioctl(struct kvm_vcpu *vcpu, unsigned long arg);
 void kvm_arch_async_pf_destroy_vcpu(struct kvm_vcpu *vcpu);
 #else
 static inline void kvm_arch_async_pf_create_vcpu(struct kvm_vcpu *vcpu) { }
@@ -799,6 +801,18 @@ static inline long kvm_arch_async_pf_hypercall(struct kvm_vcpu *vcpu,
 {
 	return SMCCC_RET_NOT_SUPPORTED;
 }
+
+static inline long kvm_arch_async_pf_vm_ioctl(struct kvm *kvm,
+					      unsigned long arg)
+{
+	return -EPERM;
+}
+
+static inline long kvm_arch_async_pf_vcpu_ioctl(struct kvm_vcpu *vcpu,
+						unsigned long arg)
+{
+	return -EPERM;
+}
 #endif
 
 /* Guest/host FPSIMD coordination helpers */
diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h
index 15499751997d..a6124068bee6 100644
--- a/arch/arm64/include/uapi/asm/kvm.h
+++ b/arch/arm64/include/uapi/asm/kvm.h
@@ -403,6 +403,25 @@ struct kvm_vcpu_events {
 #define KVM_PSCI_RET_INVAL		PSCI_RET_INVALID_PARAMS
 #define KVM_PSCI_RET_DENIED		PSCI_RET_DENIED
 
+/* Asynchronous page fault */
+#define KVM_ARM_ASYNC_PF_CMD_GET_VERSION	0
+#define KVM_ARM_ASYNC_PF_CMD_GET_SDEI		1
+#define KVM_ARM_ASYNC_PF_CMD_GET_IRQ		2
+#define KVM_ARM_ASYNC_PF_CMD_GET_CONTROL	3
+#define KVM_ARM_ASYNC_PF_CMD_SET_SDEI		4
+#define KVM_ARM_ASYNC_PF_CMD_SET_IRQ		5
+#define KVM_ARM_ASYNC_PF_CMD_SET_CONTROL	6
+
+struct kvm_arm_async_pf_cmd {
+	__u32		cmd;
+	union {
+		__u32	version;
+		__u64	sdei;
+		__u32	irq;
+		__u64	control;
+	};
+};
+
 #endif
 
 #endif /* __ARM_KVM_H__ */
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index e34fca3fa0ff..be0e6c2db2a5 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -1287,6 +1287,9 @@ long kvm_arch_vcpu_ioctl(struct file *filp,
 	case KVM_ARM_SDEI_COMMAND: {
 		return kvm_sdei_vcpu_ioctl(vcpu, arg);
 	}
+	case KVM_ARM_ASYNC_PF_COMMAND: {
+		return kvm_arch_async_pf_vcpu_ioctl(vcpu, arg);
+	}
 	default:
 		r = -EINVAL;
 	}
@@ -1364,6 +1367,9 @@ long kvm_arch_vm_ioctl(struct file *filp,
 	case KVM_ARM_SDEI_COMMAND: {
 		return kvm_sdei_vm_ioctl(kvm, arg);
 	}
+	case KVM_ARM_ASYNC_PF_COMMAND: {
+		return kvm_arch_async_pf_vm_ioctl(kvm, arg);
+	}
 	default:
 		return -EINVAL;
 	}
diff --git a/arch/arm64/kvm/async_pf.c b/arch/arm64/kvm/async_pf.c
index 4734c5b26aa8..6f763edbe3a3 100644
--- a/arch/arm64/kvm/async_pf.c
+++ b/arch/arm64/kvm/async_pf.c
@@ -464,6 +464,70 @@ long kvm_arch_async_pf_hypercall(struct kvm_vcpu *vcpu,
 	return ret;
 }
 
+long kvm_arch_async_pf_vm_ioctl(struct kvm *kvm, unsigned long arg)
+{
+	struct kvm_arm_async_pf_cmd cmd;
+	unsigned int version = 0x010000; /* v1.0.0 */
+	void __user *argp = (void __user *)arg;
+
+	if (copy_from_user(&cmd, argp, sizeof(cmd)))
+		return -EFAULT;
+
+	if (cmd.cmd != KVM_ARM_ASYNC_PF_CMD_GET_VERSION)
+		return -EINVAL;
+
+	cmd.version = version;
+	if (copy_to_user(argp, &cmd, sizeof(cmd)))
+		return -EFAULT;
+
+	return 0;
+}
+
+long kvm_arch_async_pf_vcpu_ioctl(struct kvm_vcpu *vcpu, unsigned long arg)
+{
+	struct kvm_arch_async_pf_control *apf = vcpu->arch.apf;
+	struct kvm_arm_async_pf_cmd cmd;
+	void __user *argp = (void __user *)arg;
+	long ret = 0;
+
+	if (!apf)
+		return -EPERM;
+
+	if (copy_from_user(&cmd, argp, sizeof(cmd)))
+		return -EFAULT;
+
+	switch (cmd.cmd) {
+	case KVM_ARM_ASYNC_PF_CMD_GET_SDEI:
+		cmd.sdei = apf->sdei_event_num;
+		break;
+	case KVM_ARM_ASYNC_PF_CMD_GET_IRQ:
+		cmd.irq = apf->irq;
+		break;
+	case KVM_ARM_ASYNC_PF_CMD_GET_CONTROL:
+		cmd.control = apf->control_block;
+		break;
+	case KVM_ARM_ASYNC_PF_CMD_SET_SDEI:
+		apf->sdei_event_num = cmd.sdei;
+		break;
+	case KVM_ARM_ASYNC_PF_CMD_SET_IRQ:
+		apf->irq = cmd.irq;
+		break;
+	case KVM_ARM_ASYNC_PF_CMD_SET_CONTROL:
+		if (kvm_arch_async_enable(vcpu, cmd.control) !=
+		    SMCCC_RET_SUCCESS)
+			ret = -EIO;
+
+		break;
+	default:
+		ret = -EINVAL;
+	}
+
+	if (!ret && copy_to_user(argp, &cmd, sizeof(cmd)))
+		ret = -EFAULT;
+
+	return ret;
+}
+
 void kvm_arch_async_pf_destroy_vcpu(struct kvm_vcpu *vcpu)
 {
 	kfree(vcpu->arch.apf);
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 133128d45fcb..1f161156edb2 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1569,6 +1569,9 @@ struct kvm_pv_cmd {
 /* Available with KVM_CAP_ARM_SDEI */
 #define KVM_ARM_SDEI_COMMAND   _IOWR(KVMIO, 0xc8, struct kvm_sdei_cmd)
 
+/* Available with KVM_CAP_ASYNC_PF or KVM_CAP_ASYNC_PF_INT */
+#define KVM_ARM_ASYNC_PF_COMMAND  _IOWR(KVMIO, 0xc9, struct kvm_arm_async_pf_cmd)
+
 /* Secure Encrypted Virtualization command */
 enum sev_cmd_id {
 	/* Guest initialization commands */
-- 
2.23.0